Shown below are the sequences of two strands that are adjacent to each other in an antiparallel β-sheet.

The strands are labelled “A” and “B” and the amino acids are labelled A1-A2-A3…A8 and B1-B2-B3…B8 so that we can unambiguously refer to each amino acid.

The side chains of amino acids Asp-A3 and Lys-B6 (underlined) form a salt bridge on one face of the β-sheet.